Method addData

regular_symbol.go:244–315

()

)

func (m *regularSymbol) addData() (bool, error) {
	xOffset := 1
	dir := up

	x := m.size - 2
	y := m.size - 1

	for i := 0; i < m.data.Len(); i++ {
		var mask bool
		switch m.mask {
		case 0:
			mask = (y+x+xOffset)%2 == 0
		case 1:
			mask = y%2 == 0
		case 2:
			mask = (x+xOffset)%3 == 0
		case 3:
			mask = (y+x+xOffset)%3 == 0
		case 4:
			mask = (y/2+(x+xOffset)/3)%2 == 0
		case 5:
			mask = (y*(x+xOffset))%2+(y*(x+xOffset))%3 == 0
		case 6:
			mask = ((y*(x+xOffset))%2+((y*(x+xOffset))%3))%2 == 0
		case 7:
			mask = ((y+x+xOffset)%2+((y*(x+xOffset))%3))%2 == 0
		}

		// != is equivalent to XOR.
		m.symbol.set(x+xOffset, y, mask != m.data.At(i))

		if i == m.data.Len()-1 {
			break
		}

		// Find next free bit in the symbol.
		for {
			if xOffset == 1 {
				xOffset = 0
			} else {
				xOffset = 1

				if dir == up {
					if y > 0 {
						y--
					} else {
						dir = down
						x -= 2
					}
				} else {
					if y < m.size-1 {
						y++
					} else {
						dir = up
						x -= 2
					}
				}
			}